Publish-Subscribe (“pubsub”) oriented networking, as described by Mikko Särelä, Teemu Rinta-Aho, and Sasu Tarkoma in “RTFM: Publish/Subscribe Internetworking Architecture”, published in the proceedings of ICT Mobile Summit, Stockholm, Jun. 11-13, 2008, focuses on data, as opposed to the original Internet Protocol which focuses on hosts and end points, as primary named entities. This focus on naming end points, and universal connectivity between end points, creates a number of well known problems. Firstly, the current inter-networking paradigm allows parties to communicate with each other in an open network even though some parties are outright malicious, and others selfish. Secondly, a major fraction of contemporary applications are more in the business of information dissemination than that of end-to-end, two-way communication. Finally, from a hardware point of view, in many types of networks (e.g. certain types of radio, cable, and optical networks) broadcasting or multicasting is a more natural basic operation than sending a message to a single, explicitly identified recipient. (“Multicasting” is the delivery of information to a group of specified destinations simultaneously, whereas “broadcasting” refers to transmitting information such that it may in principle be received by any device on a network.) In view of these three problems, it is proposed that inter-networking based on the publish-subscribe paradigm would be more natural, efficient, and easy-to-implement than the current sender-oriented one.
In the cases of HTTP, peer-to-peer traffic, RSS-feeds, PSIP events, Service Oriented Architecture (SOA), etc, then, looking at the data more closely, it appears that a major fraction of this (and probably other) traffic consists of fairly simple information repetition. For example, even a dynamic web page typically consists of a large number of static components that are joined together with a small amount of client-specific HTML code. In many peer-to-peer networks, a major problem is to pre-distribute the data as close as possible to the prospective consumers in an optimal way.
Generalizing, it can be argued that, with the possible exception of real-time interactive traffic such as voice calls, the majority of contemporary network traffic is data oriented. That is, the applications are not interested in creating connections but are interested in transferring well defined pieces of data. Some of the data is transactional in nature, meaning that it is short lived and is specific to the communicating parties, but the vast majority of data seems to be sender and recipient agnostic. For example, if a user wants to get the newest CNN news, the bits are basically the same (more-or-less) independent of the user's identity, and the user does not care where the bits physically come from.
The huge variety of different technologies for delivering relatively simple, even static, data is causing many problems due to lack of interoperability. The competition for the future standard of data delivery has started. Given the incentives (produced by lack of interoperability and other deficiencies within current architecture) it is expected that within 10 years, there will be some standard way of publishing and retrieving data.
One idea behind the Publish-Subscribe paradigm is that one can avoid unwanted data delivery from one node to another. Using globally unique IP addresses, as in today's network, a sender can deliver a data packet to a host identified with an IP address without any explicit request from the receiver. This causes many problems, as it results in a user receiving unwanted, and even possibly malicious, data. This problem could be overcome by abandoning receiver-based addressing, such as used in the IP address scheme, as this removes the possibility of sending data to a destination host without the destination host having requested the data. However, if the IP address scheme were abandoned it would be necessary to provide a new mechanism that can be used to route packets through the network.